Hi,
Not easily. If can edit the file listing_price of the view product via the menu Display->Views in order to add a condition on the display of the price so that you could change the text:
echo JText::_('PER_UNIT');
You could for example add a custom product field (available in the commercial versions via the menu Display->Custom fields) radio button to select which type of text to display. Suppose that you call that custom field "meter", you could use the code:
if($this->row->meter){
echo ' per meter';
}else{
echo JText::_('PER_UNIT');
}